Hydraulic device having an alignment component

ABSTRACT

The present disclosure is directed towards a hydraulic device. The hydraulic device may include a rotor, a plurality of piston members extending from the rotor, and a plurality of piston sleeves receiving the plurality of piston members. Each piston sleeve may have a piston receiving end and a piston sleeve axis. The hydraulic device may further include a plate component supporting the plurality of piston sleeves. The plate component may have a plate component axis. The hydraulic device may also include an alignment component having a plurality of arms spaced in a non-contact relationship with a piston receiving end of a respective piston sleeve when the plate component axis is parallel with the piston sleeve axis of the respective piston sleeve.

TECHNICAL FIELD

The present disclosure is directed to a hydraulic device, and moreparticularly, to a hydraulic device having an alignment component.

BACKGROUND

Hydraulic devices based on the ‘floating cup principle’ generallyinclude a shaft disposed within a housing and a rotor fixedly connectedto the shaft. The rotor includes a plurality of pistons which interactwith a plurality of piston sleeves supported by an inclined plate. Eachpiston and respective piston sleeve form a chamber, the volume of whichvaries during rotation of the shaft. The change in volume causes fluidflow into and out of the chamber via an opening in the inclined plate.

Each piston sleeve is designed to press against the inclined plate as aresult of the fluid pressure in the chamber during operation of thedevice. Centrifugal forces can cause the piston sleeve to tilt relativeto the inclined plate and form a gap at the piston sleeve-inclined plateinterface. This gap can impede pressure from building in the chamber.Furthermore, fluid present in the chamber may leak through the gap.

A conventional apparatus used to prevent fuel leakage at the pistonsleeve-inclined plate interface is disclosed in InternationalPublication No. WO/2006/083163 A1 (“the '163 publication”) to Achtenpublished on Aug. 10, 2006. The '163 publication discloses a system forclamping the piston sleeves against an inclined drum plate of a‘floating cup’ hydraulic device. Specifically, the '163 publicationdiscloses a spring plate connected to a drum plate. The spring plate isprovided with radial spring arms having contact surfaces which pressagainst a top edge of the piston sleeve. As the two spring arms pressagainst the top edge of the piston sleeve, the piston sleeve is pressedagainst the drum plate to prevent the piston sleeve from tilting duringrotation of the shaft. The force of the spring plate on the pistonsleeve is adjusted by varying the thickness of a washer disposed betweenthe spring plate and the drum plate.

Although the '163 publication may prevent the piston sleeves of thehydraulic device from excessively tipping, the limited contact areabetween the spring plate and piston sleeves may still allow a smallamount of tilt as the drum plate rotates. Further, because of theconstant spring force applied to the piston sleeves, any minor tilt oroscillation of the piston sleeves results in friction at the pistonsleeve-drum plate interface. The energy required from a power source toovercome the friction may decrease the mechanical efficiency of theoverall hydraulic device.

The present disclosure is directed to overcoming one or more of theshortcomings set forth above and/or other shortcomings in the existingtechnology.

SUMMARY

One aspect of the present disclosure is directed towards a hydraulicdevice. The hydraulic device may include a rotor, a plurality of pistonmembers extending from the rotor, and a plurality of piston sleevesreceiving the plurality of piston members. Each piston sleeve may have apiston receiving end and a piston sleeve axis. The hydraulic device mayfurther include a plate component supporting the plurality of pistonsleeves. The plate component may have a plate component axis. Thehydraulic device may also include an alignment component having aplurality of arms spaced in a non-contact relationship with a pistonreceiving end of a respective piston sleeve when the plate componentaxis is parallel with the piston sleeve axis of the respective pistonsleeve.

Another aspect of the present disclosure is directed towards a method ofassembling a hydraulic device. The method includes positioning aplurality of piston sleeves on a plate component. The method furtherincludes positioning an alignment component at a fixed distance from apiston receiving end of a respective piston sleeve. The method alsoincludes engaging the alignment component with the plate component topartially enclose the plurality of piston sleeves.

Yet another aspect of the present disclosure is directed towards afloating-cup device. The floating-cup device may include a housing and ashaft rotatably disposed within the housing. The floating-cup device mayalso include a rotor fixedly connected to the shaft, and a plurality ofpiston members extending from the rotor. The floating-cup device mayinclude a plurality of piston sleeves receiving the plurality of pistonmembers, each piston sleeve may have a bottom sleeve and a pistonreceiving end. The floating-cup device may also include a platecomponent supporting the plurality of piston sleeves. The floating cupmay further include an alignment component configured to abut againstthe plate component, the alignment component positioned to provide avariable gap with the receiving end of the respective piston sleeve, thegap varying as a function of the alignment of the respective pistonsleeve to the inclined plate component.

BRIEF DESCRIPTION OF THE DRAWINGS

J FIG. 1 is a cutaway view illustration of an exemplary disclosedhydraulic device according to the present disclosure; and

FIG. 2 is a partial cross-section of the hydraulic device of FIG. 1during a first operational conditions;

FIG. 3 is a partial cross-section of the hydraulic device of FIG. 1during a second operational condition; and

FIG. 4 illustrates an alignment component of the hydraulic device ofFIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary hydraulic device 10. In one embodiment,hydraulic device 10 may be a pump that is mechanically driven to producea flow of pressurized fluid. In an alternate embodiment, hydraulicdevice 10 may be a fluid motor that receives a flow of pressurized fluidand responsively produces a mechanical output. In either embodiment,hydraulic device 10 may include an assembly of multiple componentsincluding a housing 12, a shaft 14 supported within housing 12, a rotor16, a barrel plate component 40, and an alignment component 20.

Housing 12 may include a central bore 22 having a first end 24 and asecond end 26. Shaft 14 may extend through, for example, second end 26and be substantially axially aligned with central bore 22. Bearings 28may engage interior walls of central bore 22 to support the rotation ofthe shaft 14 therein. Shaft 14 may be sealed to the housing 12 at firstend 24. Shaft 14 may further include an opposing end protruding fromhousing 12. A motor may be coupled to the protruding end of shaft 14 if,for example, hydraulic device 10 is a hydraulic pump. Alternatively, adriving component may be coupled to the protruding end of shaft 14 if,for example, hydraulic device 10 is a motor.

Rotor 16 of hydraulic device 10 may embody a plate-like member fixedlyconnected to shaft 14 such that a rotation of shaft 14 results in adirect rotation of rotor 16. Rotor 16 may be integral to shaft 14 or,alternatively, joined to shaft 14 through welding, sintering, or otherknown metal joining processes. Rotor 16 may include a first face 30 anda second opposing face 32 oriented substantially orthogonal to the axialdirection of shaft 14.

A plurality of piston members 34 may be fixedly connected to the outerradial portion of first face 30 and second face 32 of rotor 16 in acircular pattern. Each piston member 34 may be received in a respectivepiston sleeve 36. Specifically, each piston sleeve 36 may be coupled ina sealing manner around a spherical seal (not shown) of piston member34.

The plurality of piston sleeves 36 may be connected to barrel platecomponents 40 disposed in, for example, first end 24 and second end 26of central bore 22. Barrel plate components 40 disposed in first end 24and second end 26 of central bore 22 may be connected to rotate withshaft 14. Specifically, barrel plate components 40 may be fitted aroundshaft 14 by a ball hinge and coupled to the shaft 14 by, for example, akey connection. The ball hinge allows the barrel plate components 40 towobble or tilt during rotation of shaft 14 as barrel plate components 40ride against an axial cam formed by face plates 42 disposed at first end24 and second end 26. As shaft 14, rotor 16, and barrel plate components40 rotate, each piston sleeve 36 may move toward and away from arespective piston member 34 as barrel plate components 40 wobble ortilt. This reciprocation of piston sleeves 36 with respect to the pistonmembers 34 causes an expansion and contraction of a pumping chamberlocated in piston sleeves 36. As the volume of the pumping chamberchanges, fluid may either flow into or out of the pumping chamber by wayof various ports 45 in face plates 42 and into a plurality ofdistribution passages 44 located within housing 12.

As noted above, barrel plate component 40 may be inclined to an angle βdefined by the geometry of face plates 42. In particular, face plates 42may be fixed during manufacturing at a particular tilt angle β relativeto the axis of shaft 14. Because of the assembly relationship betweenface plates 42 and barrel plate components 40, this tilt angle β maycorrespond to the volume change within piston sleeves 36 during arevolution of shaft 14. It is to be understood that face plates 42 couldbe omitted and the axial cam and ports 45 may formed directly in housing12 of hydraulic device 10.

In an alternative embodiment, hydraulic device 10 may include a variabledisplacement actuator (not shown) to adjust the tilt angle β of faceplates 42. Specifically, the variable displacement actuator may includeone or more control pistons that press against a portion of face plates42 to urge face plates 42 to tilt relative to the axial direction ofshaft 14. The control pistons associated with face plate 42 at first end24 may operated independent of the control pistons at the opposingsecond end 26 such that tilt angle β₁ associated with first end 24 maybe varied simultaneous to and independent of tilt angle β₂ associatedwith second end 26.

Referring to FIG. 2, sleeve bottom 50 of piston sleeve 36 may besupported by barrel plate component 40. Sleeve bottom 50 of pistonsleeve 36 may additionally have an opening 52 configured to fit around apositioning sleeve 54 of barrel plate component 40. Opening 52 may belarger than positioning sleeve 54, enabling piston sleeve 36 to moverelative to barrel plate component 40 during rotation of shaft 14.Additionally or alternatively, sleeve bottom 50 may have a supportingsurface 56 that may seal against a sealing surface on barrel platecomponent 40 under the influence of fluid pressure in pumping chamber38.

Alignment component 20 may be located to face a piston receiving end 60of piston sleeve 36. More particularly, alignment component 20 may bespaced in a non-contact relationship with piston receiving end 60 ofpiston sleeve 36 when a piston sleeve axis 66 is generally parallel to abarrel plate component axis 64. As indicated by axial gap 62, alignmentcomponent 20 may be positioned at least 0.0002 inches (0.00508 mm) frompiston receiving end 60, and for example between 0.0002 inches (0.00508mm) to 0.01 inches (0.254 mm) from piston receiving end 60.

The axial gap 62 will vary when piston sleeve axis 66 forms an anglerelative to barrel plate component axis 64 during, for example, rotationof shaft 14. More particularly, as piston receiving end 60 of pistonsleeve 36 approaches alignment component 20, the angle between thepiston sleeve axis 66 and barrel plate component axis 64 may increaseand the size of gap 62 may decrease. A maximum angle may be defined asthe angle between piston sleeve axis 66 and barrel plate component axis64 when piston receiving end 60 of piston sleeve 36 contacts alignmentcomponent 20. Alignment component 20 may be configured to prevent pistonsleeve 36 from tilting beyond alignment component 20. With thisconfiguration alignment component 20 may selectively contact pistonsleeve 36 without urging piston sleeve 36 into barrel plate component40. In this manner frictional losses at the piston sleeve-barrel platecomponent interface may be avoided. FIG. 3 shows piston sleeve 36tilting to the maximum angle and contacting alignment component 20.

As shown in FIG. 4, alignment component 20 may embody a plate-likemember substantially parallel to barrel plate component 40. Alignmentcomponent 20 may embody, for example, a disc having a plurality of arms72 extending from the outer perimeter of the disc. Arms 72 may form aplurality of semi-circles in the outer perimeter of alignment component20. The semi-circles may have a radius greater than the radius sized topartially receive piston members 34. Arms 72 of alignment component 20may be parallel to barrel plate component 40 and may partially orcompletely extend over piston receiving end 60 of piston sleeve 36. Asnoted above, alignment component 20 may be configured to contact pistonreceiving end 60 of piston sleeve 36 when piston sleeve 36 is tilted.The contacting surface area of alignment component 20 may depend on, forexample, the orientation of piston sleeve 36 when piston sleeve 36 istilted. Alignment component 20 may form a rigid stop for the tiltedpiston sleeves 36 without applying a force onto piston sleeve 36 to urgepiston sleeve 36 into barrel plate component 40. It is contemplated thatalignment component 20 may have any other shape known by one skilled inthe art that may be used to maintain alignment of piston sleeves 36.

Referring back to FIG. 2, alignment component 20 may be coupled tobarrel plate component 40. For example, an inner opening of alignmentcomponent 20 may form an interference fit with barrel plate component40. It is contemplated that alignment component 20 may be alternativelywelded onto barrel plate component 40, formed as one-piece with barrelplate component 40, or keyed to barrel plate component 40 to preventrelative rotation of alignment component 20 and barrel plate component40. In yet another embodiment, alignment component 20 may be fastened tobarrel plate component 40 using a threaded nut. In an alternativearrangement, alignment component 20 may be coupled to shaft 14 using anyof the means described above and/or any other conventional fasteningarrangement known to one skilled in the art.

In one embodiment, alignment component 20 may abut a radially extendingshoulder 69 of barrel plate component 40. More particularly, alignmentcomponent 20 may frictionally engage barrel plate component 40 and reston shoulder 69 of barrel plate component 40. Shoulder 69 of barrel platecomponent 40 may prevent alignment component 20 from moving towardpiston receiving end 60 of piston sleeve 36 during operation ofhydraulic device 10. It will be understood by one skilled in the artthat the height of shoulder 69 may determine the position of alignmentcomponent 20 relative to piston sleeve 36.

A retaining mechanism 68 may be attached to alignment component 20opposing shoulder 69. Retaining mechanism 68 may be configured toconstrain axial movement of alignment component 20. More particularly,retaining mechanism 68 may prevent alignment component 20 from moving ina direction away from piston receiving end 60 of piston sleeve 36.Retaining mechanism 68 may be, for example, a snap ring held in a groove79 located in barrel plate component 40. It is contemplated thatmultiple retaining mechanisms may, alternatively, be used to constrainalignment component 20.

INDUSTRIAL APPLICABILITY

The present disclosure may find application in a hydraulic device suchas, for example, a floating-cup device. Floating-cup device may be adoubled-sided (FIG. 1) or single-sided pump, motor, or transformerhaving a plurality of piston members that interact with a plurality ofcup-like piston sleeves hydrostatically supported by a barrel platecomponent. Operation of the disclosed hydraulic device is explainedbelow.

Referring to FIG. 1, as shaft 14 is rotated, rotor 16 and barrel platecomponent 40 may rotate therewith. Each piston member 34 extending fromfirst face 30 and second face 32 of rotor 16 may engage a respectivepiston sleeve 36 supported by a respective barrel plate component 40,and alter the volume of pumping chamber 38 within each piston sleeve 36.Alignment component 20 may selectively contact piston sleeve 36 tomaintain alignment of piston sleeve 36 during rotation of shaft 14.

More particularly, when shaft 14 is rotated, sealing surface 56 ofpiston sleeve 36 may press against barrel plate component 40 in a mannersuch that piston sleeve axis 66 may be substantially parallel to barrelplate component axis 64. During such instances, alignment component 20may form a non-contact relationship with piston receiving end 60 ofpiston sleeve 36.

During rotation of shaft 14 or, alternatively, when pressurized fluid inchamber 38 is low, piston sleeve 36 may tilt relative to barrel platecomponent 40. Specifically, piston sleeve axis 66 may form an anglerelative to barrel plate component axis 64. In such instances, the axialgap 62 between alignment component 20 and piston receiving end 60 ofpiston sleeve 36 may change. Gap 62 may vary as a function of thealignment of piston sleeve 36. When piston sleeve 36 tilts beyond apredetermined angle, i.e., maximum angle between piston sleeve axis 66and barrel plate component axis 64, alignment component 20 is contactedby piston receiving end 60 of piston sleeve 36. The contact can takeplace at any point on the alignment component 20 depending on theorientation of tilt of piston sleeve 36.

Gap 62 between alignment component 20 and piston receiving end 60 ofpiston sleeve 36 may allow for minor tilting of piston sleeve 36.Alignment component 20, however, may prevent piston sleeve 36 fromtilting beyond a predetermined angle and, in this manner, may preventfluid leakage at the interface between piston sleeve 36 and barrel platecomponent 40. Thus, piston sleeve 36 may selectively contact alignmentcomponent 20 with such selective contact minimizing frictional losses atthe piston sleeve 36-barrel plate component 40 interface. This mayimprove the overall efficiency of hydraulic device 10.

Application of the disclosed alignment component 20 may also provide fora simple assembly of hydraulic device 10 by, for example, removing thenecessity for a plurality of fasteners and springs. Furthermore, thedisclosed device may reducing manufacturing costs of the associatedcomponents. For example, barrel plate component 40 of the present devicemay be formed by lathe turning and lapping operations, and alignmentcomponent 20 may be formed by stamping and finished by grinding/lapping.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the hydraulic device of thepresent disclosure without departing from the scope of the disclosure.Other embodiments will be apparent to those skilled in the art fromconsideration of the specification and practice of the hydraulic devicedisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the disclosure beingindicated by the following claims and their equivalents.

1. A hydraulic device, comprising: a rotor; a plurality of pistonmembers extending from the rotor; a plurality of piston sleevesreceiving the plurality of piston members, each piston sleeve having apiston receiving end and a piston sleeve axis; a plate componentsupporting the plurality of piston sleeves, the plate component having aplate component axis; and an alignment component having a plurality ofarms spaced in a non-contact relationship with the piston receiving endof a respective piston sleeve when the plate component axis is parallelwith the piston sleeve axis of the respective piston sleeve.
 2. Thehydraulic device of claim 1, wherein the plurality of arms form avariable gap with the piston receiving end of the respective pistonsleeve, the gap varying as a function of a tilt of the piston sleeveaxis relative to the plate component axis.
 3. The hydraulic device ofclaim 1, wherein the plurality of arms form a rigid stop for the pistonreceiving end of the respective piston sleeve.
 4. The hydraulic deviceof claim 1, wherein the plurality of arms form a plurality of openingsthat receive the piston members.
 5. The hydraulic device of claim 3,wherein the plurality of arms partially extend over the respectivepiston sleeve.
 6. The hydraulic device of claim 1, wherein the alignmentcomponent contacts a radially extending shoulder of the plate component.7. The hydraulic device of claim 6, wherein an inner circumference ofthe alignment component forms an interference fit with the radiallyextending shoulder of the plate component.
 8. The hydraulic device ofclaim 7, further including a mechanism configured to retain thealignment component.
 9. The hydraulic device of claim 1, wherein thehydraulic device is a floating-cup device.
 10. A method of assembling ahydraulic device, comprising: positioning a plurality of piston sleeveson a plate component; positioning an alignment component at a fixeddistance from a piston receiving end of a respective piston sleeve; andengaging the alignment component with the plate component solely at theinner circumference of the alignment component.
 11. The method of claim9, further including receiving a plurality of piston members in aplurality of openings disposed within the alignment component tomaintain the position of the plurality of piston members within theplurality of piston sleeves.
 12. The method of claim 11, whereinengaging the alignment component with the plate component includesfrictionally engaging an inner circumference of the alignment componentwith a groove disposed within a wall of the plate component.
 13. Themethod of claim 12, wherein engaging the alignment component with theplate component further includes retaining the alignment component witha snap ring.
 14. The method of claim 10, wherein engaging the alignmentcomponent with the plate component includes keying the alignmentcomponent to the plate component so that the alignment component rotateswith the plate component during operation of the hydraulic device.
 15. Afloating-cup device, comprising: a housing; a shaft rotatably disposedwithin the housing; a rotor fixedly connected to the shaft; a pluralityof piston members extending from the rotor; a plurality of pistonsleeves receiving the plurality of piston members, each piston sleevehaving a piston receiving end; a plate component supporting theplurality of piston sleeves; and an alignment component configured toabut against the plate component and provide a variable gap with thepiston receiving end of the respective piston sleeve, the gap varying asa function of the alignment of the respective piston sleeve to the platecomponent.
 16. The floating-cup device of claim 15, wherein thealignment component partially extends over the respective piston sleeve.17. The floating-cup device of claim 15, wherein the alignment componentincludes a plurality of openings in a circumference of the alignmentcomponent for receiving the plurality of piston members.
 18. Thefloating-cup device of claim 15, further including a retaining mechanismconfigured to constrain axial movement of the alignment component. 19.The floating-cup device of claim 15, wherein the alignment component ispositioned between 0.0002 inches to 0.01 inches from the pistonreceiving end of the respective piston sleeve when the respective pistonsleeve is in alignment with the plate component.
 20. The floating-cupdevice of claim 19, wherein the alignment component is positioned toform a rigid stop for the piston sleeve when an axis of the respectivepiston sleeve tilts to a predetermined angle relative to an axis of theplate component.